1. To make the crust, blend the flour, sugar, salt, and butter in a food processor or an electric mixer with the paddle attachment until the butter lumps are no larger than peas. Whisk the egg yolks in a small measuring cup and add enough water to make 1/4 cup liquid; add to flour mixture. Mix until the dough just starts to come together. (DT:I had to add another couple tablespoons water to get the dough to come together. I also used ice cold water.) Gather the dough, shape into a disc, and wrap in plastic. Chill for at least 1 hour or up to 3 days.

2. To make the streusel, combine the butter, almond paste, sugar, flour, and cinnamon in food processor and process until the mixture is in fine crumbles. (Alternatively, use a pastry blender.) Refrigerate until needed.

3. Allow the dough to stand at room temperature for 5 minutes. Roll on a lightly floured surface into a 1/2-inch-thick disc, frequently rotating the dough to prevent sticking. Transfer to a 9-inch tart pan with removable bottom. Ease the dough into the pan, fitting it to the pan’s contour with fingertips, leaving some dough hanging over the edges. Trim the pastry edges by rolling the pin over the rim and discard trimmings. Freeze the shell until firm, about 30 minutes.

4. Preheat the oven to 375 degrees.

5. Make the rhubarb filling by combining the rhubarb, brown sugar, and cinnamon in a large sauté pan. Cook over medium heat, stirring frequently, until the rhubarb is fall-apart tender, about 10 minutes.

6. Fill the tart shell with the rhubarb mixture to within 1/2 inch from the top of the crust. Sprinkle on the streusel and transfer to a baking sheet. Bake until the streusel is golden brown and the filling is bubbly, about 45 minutes. Transfer the tart shell to a wire rack and cool completely. Using a small sharp knife, gently loosen the crust from sides of pan. Push up pan bottom to release tart. Serve with ice cream.

1. In a small saucepan, scald the half-and-half over medium-low heat until hot.

2. Whisk the brown sugar and egg yolks together in a medium bowl. Slowly whisk in the half-and-half.

3. Return the mixture to the saucepan and cook over medium-low heat, stirring constantly with a rubber spatula until the mixture thickens enough to coat it, about 5 minutes.

4. Strain the mixture through a fine-mesh sieve into a metal bowl. Refrigerate until cold, then whisk the sour cream into the half-and-half mixture and freeze in an ice cream maker according to manufacturer’s instructions.